This invention relates to the field of oil production, and provides a system and method for generating steam downhole in an oil well, to enhance production. The invention is especially suitable for producing heavy oil from oil sands.
The production of oil from a reservoir slows down as the reservoir is depleted, because the remaining oil is more viscous, and flows more slowly towards the production well. Some reservoirs have heavy oil which flows slowly from the beginning.
It has been known, in the prior art, to inject steam into a reservoir, to heat the oil, reducing its viscosity, and to drive the oil towards the production well. U.S. Pat. Nos. 4,445,570 and 4,545,430, the disclosures of which are incorporated herein, disclose systems used in downhole steam generators.
The present invention provides an improvement over the prior art, insofar as it discloses a system which does not require the downhole burning of hydrocarbons for production of heat for generating steam.